
Bought these a few years ago and they were great; the seal in the lids was polyethylene, slightly tapered and turned inward. They close well even after many uses. However, this second order has a thin foam gasket that leaks slightly. I have to make sure they stay upright, but if they leak liquids they will also leak vapor that builds up. Both vials look the same except for the seal. Be sure to double check what you are ordering; I would have sent them back but the deadline expired before I noticed the defect.

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